kernel/tools/perf/util/map.c, branch linux-5.1.y

perf tools: Fix map reference counting

2019-04-17T17:30:11Z

By calling maps__insert() we assume to get 2 references on the map, which we relese within maps__remove call. However if there's already same map name, we currently don't bump the reference and can crash, like: Program received signal SIGABRT, Aborted. 0x00007ffff75e60f5 in raise () from /lib64/libc.so.6 (gdb) bt #0 0x00007ffff75e60f5 in raise () from /lib64/libc.so.6 #1 0x00007ffff75d0895 in abort () from /lib64/libc.so.6 #2 0x00007ffff75d0769 in __assert_fail_base.cold () from /lib64/libc.so.6 #3 0x00007ffff75de596 in __assert_fail () from /lib64/libc.so.6 #4 0x00000000004fc006 in refcount_sub_and_test (i=1, r=0x1224e88) at tools/include/linux/refcount.h:131 #5 refcount_dec_and_test (r=0x1224e88) at tools/include/linux/refcount.h:148 #6 map__put (map=0x1224df0) at util/map.c:299 #7 0x00000000004fdb95 in __maps__remove (map=0x1224df0, maps=0xb17d80) at util/map.c:953 #8 maps__remove (maps=0xb17d80, map=0x1224df0) at util/map.c:959 #9 0x00000000004f7d8a in map_groups__remove (map=, mg=) at util/map_groups.h:65 #10 machine__process_ksymbol_unregister (sample=, event=0x7ffff7279670, machine=) at util/machine.c:728 #11 machine__process_ksymbol (machine=, event=0x7ffff7279670, sample=) at util/machine.c:741 #12 0x00000000004fffbb in perf_session__deliver_event (session=0xb11390, event=0x7ffff7279670, tool=0x7fffffffc7b0, file_offset=13936) at util/session.c:1362 #13 0x00000000005039bb in do_flush (show_progress=false, oe=0xb17e80) at util/ordered-events.c:243 #14 __ordered_events__flush (oe=0xb17e80, how=OE_FLUSH__ROUND, timestamp=) at util/ordered-events.c:322 #15 0x00000000005005e4 in perf_session__process_user_event (session=session@entry=0xb11390, event=event@entry=0x7ffff72a4af8, ... Add the map to the list and getting the reference event if we find the map with same name. Signed-off-by: Jiri Olsa Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Alexei Starovoitov Cc: Andi Kleen Cc: Daniel Borkmann Cc: Eric Saint-Etienne Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Song Liu Fixes: 1e6285699b30 ("perf symbols: Fix slowness due to -ffunction-section") Link: http://lkml.kernel.org/r/20190416160127.30203-10-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Check maps for bpf programs

2019-04-17T17:30:11Z

As reported by Jiri Olsa in: "[BUG] perf: intel_pt won't display kernel function" https://lore.kernel.org/lkml/20190403143738.GB32001@krava Recent changes to support PERF_RECORD_KSYMBOL and PERF_RECORD_BPF_EVENT broke --kallsyms option. This is because it broke test __map__is_kmodule. This patch fixes this by adding check for bpf program, so that these maps are not mistaken as kernel modules. Signed-off-by: Song Liu Reported-by: Jiri Olsa Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Alexei Starovoitov Cc: Andi Kleen Cc: Andrii Nakryiko Cc: Daniel Borkmann Cc: Martin KaFai Lau Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Yonghong Song Link: http://lkml.kernel.org/r/20190416160127.30203-8-jolsa@kernel.org Fixes: 76193a94522f ("perf, bpf: Introduce PERF_RECORD_KSYMBOL") Signed-off-by: Jiri Olsa Signed-off-by: Arnaldo Carvalho de Melo

perf maps: Purge all maps from the 'names' tree

2019-03-19T19:52:05Z

Add function __maps__purge_names() to purge all maps from the names tree. We need to cleanup the names tree in maps__exit(). Detected with gcc's ASan. Signed-off-by: Changbin Du Reviewed-by: Jiri Olsa Cc: Alexei Starovoitov Cc: Daniel Borkmann Cc: Eric Saint-Etienne Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Steven Rostedt (VMware) Fixes: 1e6285699b30 ("perf symbols: Fix slowness due to -ffunction-section") Link: http://lkml.kernel.org/r/20190316080556.3075-12-changbin.du@gmail.com Signed-off-by: Arnaldo Carvalho de Melo

perf map: Remove map from 'names' tree in mapsremove()

2019-03-19T19:52:05Z

There are two trees for each map inserted by maps__insert(), so remove it from the 'names' tree in __maps__remove(). Detected with gcc's ASan. Signed-off-by: Changbin Du Reviewed-by: Jiri Olsa Cc: Alexei Starovoitov Cc: Daniel Borkmann Cc: Eric Saint-Etienne Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Steven Rostedt (VMware) Fixes: 1e6285699b30 ("perf symbols: Fix slowness due to -ffunction-section") Link: http://lkml.kernel.org/r/20190316080556.3075-11-changbin.du@gmail.com Signed-off-by: Arnaldo Carvalho de Melo

perf map: Move structs and prototypes for map groups to a separate header

2019-02-06T13:00:38Z

And since machine.h only needs what is in there, make it stop including map.h and instead include this newly introduced map_groups.h instead. Cc: Adrian Hunter Cc: Jiri Olsa Cc: Namhyung Kim Link: https://lkml.kernel.org/n/tip-dbob25fv5rp2rjpwlnterf38@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf symbols: Use cached rbtrees

2019-01-25T14:12:10Z

At the cost of an extra pointer, we can avoid the O(logN) cost of finding the first element in the tree (smallest node). Signed-off-by: Davidlohr Bueso Tested-by: Arnaldo Carvalho de Melo Cc: Jiri Olsa Cc: Namhyung Kim Link: http://lkml.kernel.org/r/20181206191819.30182-6-dave@stgolabs.net Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Support 'srccode' output

2018-12-17T17:57:07Z

When looking at PT or brstackinsn traces with 'perf script' it can be very useful to see the source code. This adds a simple facility to print them with 'perf script', if the information is available through dwarf % perf record ... % perf script -F insn,ip,sym,srccode ... 4004c6 main 5 for (i = 0; i < 10000000; i++) 4004cd main 5 for (i = 0; i < 10000000; i++) 4004c6 main 5 for (i = 0; i < 10000000; i++) 4004cd main 5 for (i = 0; i < 10000000; i++) 4004cd main 5 for (i = 0; i < 10000000; i++) 4004cd main 5 for (i = 0; i < 10000000; i++) 4004cd main 5 for (i = 0; i < 10000000; i++) 4004cd main 5 for (i = 0; i < 10000000; i++) 4004b3 main 6 v++; % perf record -b ... % perf script -F insn,ip,sym,srccode,brstackinsn ... main+22: 0000000000400543 insn: e8 ca ff ff ff # PRED |18 f1(); f1: 0000000000400512 insn: 55 |10 { 0000000000400513 insn: 48 89 e5 0000000000400516 insn: b8 00 00 00 00 |11 f2(); 000000000040051b insn: e8 d6 ff ff ff # PRED f2: 00000000004004f6 insn: 55 |5 { 00000000004004f7 insn: 48 89 e5 00000000004004fa insn: 8b 05 2c 0b 20 00 |6 c = a / b; 0000000000400500 insn: 8b 0d 2a 0b 20 00 0000000000400506 insn: 99 0000000000400507 insn: f7 f9 0000000000400509 insn: 89 05 29 0b 20 00 000000000040050f insn: 90 |7 } 0000000000400510 insn: 5d 0000000000400511 insn: c3 # PRED f1+14: 0000000000400520 insn: b8 00 00 00 00 |12 f2(); 0000000000400525 insn: e8 cc ff ff ff # PRED f2: 00000000004004f6 insn: 55 |5 { 00000000004004f7 insn: 48 89 e5 00000000004004fa insn: 8b 05 2c 0b 20 00 |6 c = a / b; Not supported for callchains currently, would need some layout changes there. Committer notes: Fixed the build on Alpine Linux (3.4 .. 3.8) by addressing this warning: In file included from util/srccode.c:19:0: /usr/include/sys/fcntl.h:1:2: error: #warning redirecting incorrect #include to [-Werror=cpp] #warning redirecting incorrect #include to ^~~~~~~ cc1: all warnings being treated as errors Signed-off-by: Andi Kleen Tested-by: Jiri Olsa Link: http://lkml.kernel.org/r/20181204001848.24769-1-andi@firstfloor.org Signed-off-by: Arnaldo Carvalho de Melo

perf map: Remove extra indirection from map__find()

2018-12-17T17:53:57Z

A double pointer is used in map__find() where a single pointer is enough because the function doesn't affect the rbtree and the rbtree is locked. Signed-off-by: Eric Saint-Etienne Acked-by: Jiri Olsa Cc: Alexander Shishkin Cc: Eric Saint-Etienne Cc: Namhyung Kim Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/1542969759-24346-1-git-send-email-eric.saint.etienne@oracle.com Signed-off-by: Arnaldo Carvalho de Melo

perf symbols: Fix slowness due to -ffunction-section

2018-11-22T01:39:59Z

Perf can take minutes to parse an image when -ffunction-section is used. This is especially true with the kernel image when it is compiled this way, which is the arm64 default since the patcheset "Enable deadcode elimination at link time". Perf organize maps using a rbtree. Whenever perf finds a new symbols, it first searches this rbtree for the map it belongs to, by strcmp()'aring section names. When it finds the map with the right name, it uses it to add the symbol. With a usual image there aren't so many maps but when using -ffunction-section there's basically one map per function. With the kernel image that's north of 40,000 maps. For most symbols perf has to parses the entire rbtree to eventually create a new map and add it. Consequently perf spends most of the time browsing a rbtree that keeps getting larger. This performance fix introduces a secondary rbtree that indexes maps based on the section name. Signed-off-by: Eric Saint-Etienne Reviewed-by: Dave Kleikamp Reviewed-by: David Aldridge Reviewed-by: Rob Gardner Cc: Alexander Shishkin Cc: Jiri Olsa Cc: Namhyung Kim Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/1542822679-25591-1-git-send-email-eric.saint.etienne@oracle.com Signed-off-by: Arnaldo Carvalho de Melo

Merge tag 'v4.19-rc5' into perf/core, to pick up fixes

2018-09-25T09:19:44Z

Signed-off-by: Ingo Molnar